This example shows a multi-series line chart of daily temperatures for New York, San Francisco, and Austin, with two interactive features. Hovering over a city’s label highlights its line by increasing stroke width and graying out the others, while clicking the label toggles that city’s line visibility. The visualization uses d3.line with curveBasis to draw smooth paths, d3.scaleTime and d3.scaleLinear for axes, and d3.schemeCategory10 for colors. Data is loaded as a TSV file via d3.tsv, and all rendering is done in SVG.